Hoist



Fel 23, 1954 F. w. coFr-'ING HOIST 3 Sheets-Sheet 1 Filed Oct. 27, 1951Feb. 23, 1954 F. w. COFFING 2,670,176

HoIsT Filed Oct. 27, 1951 3 Sheets-Sheet 2 INVEN TOR. FRfoK/av I4((aff/YG Feb. 23, 1954 F W, COFFING 2,670,176

HOIST Filed Oct. 27, 1951 3 Sheets-Sheet 3 IN1/EN TOR. feine/cr W.(oFF/Na Patented Feb. 23, 1954 HOIST Fredrick W. (loilng, Danville,Ill., assigner to Ceiling Hoist Company, Danville, Ill., a corporationApplication Uctober 27, 1951, Serial No. 253,531

7 Claims.

The present invention relates to improvements in hoisting apparatus, andmore specically to lever operated chain hoists.

In my co-pending application filed March 15, 1951, bearing Serial No.215,700 I have shown, described and claimed a lever operated chain hoistwherein the hoisting mechanism may be readily and easily shifted to loadraising condition, to load lowering condition or to iree runningcondition when it is the desire of the operator to establish theseconditions.

It is one of the objects oi the present invention to provide a chainhoist having characteristics oi the hoist described and claimed in saidapplication, but which may be more simply constructed, shall have feweroperated parts, and which will have the equivalent load lifting powerand which may be embodied in a more compact construction.

For the purpose' of disclosing my invention I have illustrated anembodiment thereof in the accompanying drawings in which:

Fig. 1 is a transverse sectional view o! a hoist embodying my invention,

Fig. 2 is a longitudinal sectional view taken on the line 2-2 oi Fig. 1,and y Fig. 3 is a longitudinal sectional view taken on the line 3--3 atFig. 1, certain oi' its parts being shown in dotted lines for thepurpose ci clarity.

Fig. 4 is a fragmentary view showing parts of the hoist in load raisingposition.

Fig. 5 is the same as Fig. 4, yshowing them in load lowering positionwith the holding pawl freed.

Fig. 6 is the same as Fig. 5 showing the parts in load lowering positionwith the load pawl released.

In the embodiment illustrated I provide a housing lll having a frontplate closing member il secured in place by suitable holding screws i2shown in Fig. 2. The housing is provided with an offset portion I3,which provides a housing for the load chain sheave I4, over which isadapted to ride the 'link chain I5. This chain feeds through suitableopenings in the bottom oi the offset I3.

The chain sheave i4 is mounted on a shaft IB, one end of which ismounted in a bearing `i'l in the housing l0. On the opposite side oi'the sheave I4 the shaft I6 is provided with an enlarged portion I8operating in a bearing I8 supported in a dividing wall of the housingI0. The shaft I8 is extended in reduced diameter, and the opposite endthereof extends into a bearing 2|) in the vcover plate Il. Mounted onthe shaft extension is a ratchet wheel 2l which is keyed on the shaft I8and, therefore, is rotatable With the sheave I4.

The housing is provided at its top with a swivel hook 22. the end 23(see Fig. 2) of which extends through the housing to be engaged by aholding nut 24 for maintaining the hook against vertical displacement.

The ratchet wheel 2| is operated and controlled respectively by handlepawl 25 (see Fig. 2) and a holding pawl 26. The holding pawl is mountedon a stud 21 extending between the side walls of the housing. The end ofthe pawl is adapted to engage the teeth 21a of the ratchet wheel 2|.This holding pawl is biased in an engaging direction by coiled spring 29coiled around the stud 21 and having one end bearing against the insidewall of the housing and the other end hooked over the back of theholding pawl.

The load pawl 25 is disposed between and carried by a pair of arms 28swingably mounted upon the shaft i6 and disposed on opposite sides ofthe ratchet wheel 2 I The pawl is pivoted upon a stud 30 fixed betweenthe arms 28 and has its free end biased in a tooth engaging direction bycoiled spring 3|. One end of this spring is secured to a pin 32 on theinner face of one of the arms 28, and its opposite end is connected to apin 33 on the inner edge of the pawl.

The free ends of the arms 28 are connected by a link 34 with anoscillating lever arm 35. To this end, one end of the link 34 ispivotally connected by a pin 36 extending between the free ends of thearms 28, and the opposite end extends between bifurcated ends oi thelever arm S5 and is pivotally connected to the lever arm by a pin 31.This lever arm 35 is a part oi' an oscillating shaft 3B (see Figs. 1 and2) having one end jcurnalled at 39 in a side wall of the housing, andthe other end enlarged as at 4l) and extending through a bearing 4I inthe cover plate Il, see Fig. l. The outer end of this eniarged portion40 has a lever arm receiving opening 42 through which may be passed anoperating lever arm 43, and which is adjustably slideable through theopening so that the lever length oi the same may be adjusted or thedirection of lever operation may be changed by sliding the lever fromone extremity to the other. 43a are retainers to avoid passing lever 43entirely out of lever arm receiving opening 42. The lever arm 43 ismaintained in its adjusted position through the medium of a set screw44.

For controlling the various positions of the holding pawl 26 and theload pawi 25, I provide a reversing ring 46 (shown in Figs. 1 and v2)which is rotatably mounted on an extension 4E of the bearing for theshaft portion I8. This reversing ring is provided with an operating cam41 (see Fig. 2) for operating and controlling the position of theholding pawl 25. The holding pawi 25 is provided with a pin 48 whichprojects into the path of a cam 41 to be engaged by said cam when thereversing ring 45 is moved to a predetermined position by spring I.

A cam 49 oppositely disposed relative to the cam 41 (see Fig. 2) on thereversing ring 45 is adapted to control the position of the load pawl25. This cam is adapted to engage a pin 5I! on the load pawl 25 whichextends through a slot 28a in one of the arms 28 and into the path ofthe cam 45 to be engaged thereby when the reversing ring is moved topredetermined position by spring 5I.

The reversing ring 45 is biased in a direction to cause the cam 41 toengage the pin 48 by a coiled spring 5i, one end of which is anchored toa pin 52 secured in the casing, and the other end of which is connectedto a lug 53 on the reversing ring 45. This spring biases the reversingring 45 in a counterclockwise direction, looking at Fig. 2. Thereversing ring 45 is moved in a clockwise direction through the mediumof a cam member 54 which is rotatably mounted on a shaft 55 providedwith an operating handle 56 which is exterior of the casing. The cammember 54 is adapted when rotated counterclockwise by the handle 56 toengage an arm 51 on the reversing ring and rotate the reversing ringclockwise thereby insuring the disengagement of the cani members 41 and49 from their respective pawls.

In order to give an additional kick to the ring to cause the same torotate counterclockwise in addition to the influence of the spring 5iwhen the cam member 54 is disengaged from the arm 51, I provide a springpressed plunger 58 operating in a cylinder 59 and adapted to be engagedand the spring controlling the same compressed by the lug 53 when thereversing ring is moved in a clockwise direction.

It will be observed that by oscillating the hand lever 43 through shaft38, the operating lever arm 35 will be oscillated, and in turn willoscillate the load pawl carrying arms 28 through the link 34. Said armswill thereby be caused to oscillate the load pawl about the axis of thesheave I4 relative to the teeth Zia oi the ratchet wheel 2I.

For raising the load, as shown in Fig. 4, the reversing ring 45 has beenrotated clockwise by the engagement of the cam 54 with the arm 51 tomove the cam member 41 and the cam member 43 out of position to engagethe holding pawl 26 or the load pawl 25. Thereupon, these respectivepawls are adapted to ratchet on the teeth 2 la of the ratchet wheel 2 I.Under these circumstances the holding pawl 26 will be in engagement withthe teeth of the ratchet wheel thereby holding the same againstclockwise rotation under the influence of a load carried by the load endof the chain l5. If now the handle lever 43 be raised or moved clockwiseto the hoist, this will rotate the lever 35 in a clockwise direction andthrough the link 34 the arms 28 will be raised, thus causing the pawl 25to ride the teeth 2Ia.. As soon, however, as the direction of movementof the handle lever 43 is reversed, the arms 2B will be lowered in acounterclockwise direction with the pawl 25 biting into the teeth 2 l aof the ratchet 2l thereby rotating the ratchet and with it the chainsheave elevating the load. During this movement the holding pawl willratchet over the teeth d being, however, in a condition to lock into theteeth as soon as the load is released by releasing the downward pressureon the handle 43. By repeated oscillations of the handle 43 the loadwill be raised.

If, however, it be desired to lower the load, the handle 5E is moved tothe position illustrated in Fig. 5, reversing the position of cam 54relative to the arm 51, and the coiled spring 5I will bias the reversingring in a counterclockwise direction, or in a direction to cause thepawl member 41 to engage the pin 4S. With the parts illustrated in Figs.2 and 6, the holding pawl 2G has taken the load, being in engagementwith one of the teeth 2id of the ratchet Wheel 2| and the reversing ringhas been biased to the position illustrated in said figures. With theparts in this position, by elevating the handle 43 and, accordingly,rocking the pawl carrying arms 28 upwardly, the pawl 25 being free fromthe load drag, and due to the position of the cam member 49, will ridethereover out of engagement with the teeth 2 la.

Due to the fact that the pin 53 in load pawl 25 has ridden onto the topof the cam 49, the reversing ring is free to be moved further in acounterclockwise direction to cause the cam 41 to lift the pin 4B onholding pawl 26, as shown in Fig. 5. The lever 43 having been raised, aslight downward movement thereof will eiect. a corresponding slightdownward movement of the arms 28. The load pawl will then be cammedforwardly to engage the next tooth of the ratchet and by slightly takingthe load 01T the holding paal 25 by this reverse movement. said holdingpawl will be kicked out oi tooth engagement by the cam member 41engaging pin 48. Upon again raising lever 43, with the pawl 25 inengagement with the teeth 2 I a, the load may be lowered thereby, thelowering action being controlled by the lever 43 and pawl 25.Accordingly, by continued operation of the lever 43 in ratchet style,the load may be controlledly lowered step by step.

For permitting the ratchet wheel 2| to rotate freely and thereby permitfree chaining of the hoist with no load thereon, I provided a throwoutmeans operable from the exterior o the casing to throw out the handlepawl 25, as shown in Fig. 3. This throw-out means comprises a spring arm58a iixedly secured by an eye to the pin 59a and biased by its inherentresiliency into an inoperative position. The spring arm extendsdownwardly past the pin 5I) and its lower end is adapted to be engagedby an operating lever mounted interiorly of the casing on the inner endof a rotatable shaft 5I. This shaft extends to the exterior of thecasing and carries an operating handle E2. Therefore, when the operatinghandle 62 is operated in a counterclockwise direction it overcomes thebias of the spring arm 58a and moves the same against the pin 5U.However, when the operating lever is moved in the opposite direction,the natural bias of the spring arm 58a will cause its movement in adirection to release pin 50 and the load pawl 25.

Thus, for the free chaining operation, with no load on the hoist andwith lever 43 in any position, but with handle 5B in load loweringposition, the handle 62 may be swung in counterclockwise direction. Thisrotates lever 6i) to force the spring 58a clockwise about pin 59a tooperating engagement with pin 50 of pawl 25. This action will lift pawl25 free of engagement with the ratchet teeth 2Ia. Thus, with the holdingpawll awaits maintamed in disengaged'position by the cam 41 and the loadpawl 25 maintained in disengaged position by the spring arm 58a, theload chain is free to move in either direction.

The invention claimed is:

1. A lever operated chain hoist including in combination a chain sheave,a rotatable ratchet wheel controlling the rotation of said sheave, meansfor restraining said Wheel from rotating in one direction, a load patvlcarrying arm oscillatable about an axis coincident with the axis of saidratchet wheel, a load pawl pivotally mounted on said arm and engageablewith the teeth of said ratchet wheel, a pivotally mounted operatinglever arm, a link connecting the free end of said operating lever armwith the free end of said load pawl carrying arm, and means foroscillating said operating lever arm.

2. A lever operated chain hoist including in combination a chain sheave.a shaft on which said sheave is mounted, a ratchet wheel mounted on saidshaft, a pivotally mounted holding pawl engageable with the teeth ofsaid ratchet wheel, means for biasing said holding pawl into engagementwith said ratchet wheel, a load pawl carrylng arm oscillatably mountedon said shaft, a load pawl pivotally mounted on said carrying arm, meansfor biasing said load pawl into engagement with said ratchet Wheel, anoperating lever arm for oscillating said load pawl carrying arm, meansfor pivotally mounting one end of said operating lever arm, a linkconnecting the opposite end of said operating lever arm with the freeend of said load pawl carrying arm, a handle carried by the pivotalmounting means of said operating lever arm for oscillating saidoperating lever arm, and a reversing ring oscillatable about the axis ofsaid shaft for controlling the effectiveness of the biasing means oisaid pawls.

3. In combination. a load suporting wheel having ratchet teeth, aholding pawl engageable with said teeth, a load pawl engageable withsaid teeth and oscillatable about the axis of said wheel for controllingthe rotation thereof. means for normally biasing said pawls in rachettooth engaging direction, a movable cam member normally biased toholding pawl engagement for maintaining said holding pawl innon-engaging position, a manually operable member for locking said camagainst its bias engagement with said holding pawl, a pivotally mountedspring arm mounted for engagement with said load pawl, and a manuallyoperable lever connected with said spring arm for moving said arm intoengagement with said load pawl in a direction to move the same out ofengaging position with respect to said ratchet teeth.

4. A lever operated chain hoist including in combination a chain sheave,a rotatable ratchet wheel controlling the rotation of said sheave, apivotally mounted holding pawl normally biased into engagement Awith theteeth of said ratchet wheel, a load pawl carrying arm pivotally mountedabout the axis of said sheave and extending radially therefrom, a loadpawl pivotally mounted on said arm and engageable with the teeth of saidratchet wheel, a handle operated lever arm pivotally mounted adjacentthe periphery of said sheave and said pawl carrying arm, a linkconnecting the free ends of said lever arm and pawl carrying arrn,whereby said pawl carrying arm will be oscillated about the axis of saidsheave upon oscillation of said lever arm about an axis adjacentthereto, and a spring connecting said load pawl and pawl carrying armfor normal- 6 1y biasingfsaid load pawl m ratchet tootli engagement.

5. A lever operated chain hoist including a chain sheave, a housingmounting said sheave for rotation therein, a rotatable ratchet toothwheel rotatable with and oifset axially of said sheave within saidhousing, a holding pawl pivotally mounted in said housing normallybiased into ratchet tooth engagement for restraining said wheel fromrotation in on-e direction. a load pawl carrying ann pivotally mountedaxially of said ratchet wheel and adjacent thereto to extend radiallytherefrom and oscillate thereabout within said housing, a load pawlpivotally mounted on said arm normally biased into ratchet toothengagement, a handle operated lever arm pivotally mounted Within saidhousing closely adjacent said ratchet wheel and pawl carrying arm, anda, link mounted within said housing connecting the free end of saidlever arm with the free end of said load pawl carrying arm, wherebyoscillation of said lever arm Within said housing will effectoscillation of said pawl carrying arm and load pawl about the axis ofsaid sheave.

6. A lever operated chain hoist including a chain sheave, a housingmounting said sheave for rotation therein, a rotatable ratchet toothwheel rotatable with and offset axially of said sheave Within saidhousing, a holding pawl pivotally mounted in said housing normallybiased into ratchet tooth engagement for restraining said wheel fromrotation in one direction, a load pawl carrying arm pivotally mountedaxially of said ratchet wheel and adjacent thereto to extend radiallytherefrom and oscillate thereabout within said housing, a load pawlpivotally mounted on said arm normally biased into ratchet toothengagement, a reversing ring mounted for concentric movement about theaxis of said sheave having opposed cam lobes, a spring for biasing saidring under tension in a direction for camming engagement with said pawlsto alternately move them out of ratchet tooth engagement, a manuallyoperated control member for locking said ring in inoperative positionagainst spring tension, a handle operated lever arm pivotally mountedwithin said housing closely adjacent said ratchet wheel and pawlcarrying arm, and a link mounted within said housing connecting the freeend of said lever arm with the free end of said load pawl carrying arm,whereby oscillation of said lever arm within said housing will effectoscillation of said pawl carrying arm and load pawl about the axis ofsaid sheave.

7. A lever operated chain hoist including a chain sheave, a housingmounting said sheave for rotation therein, a rotatable ratchet toothwheel rotatable with and offset axially of said sheave within saidhousing, a holding pawl pivotally mounted in said housing normallybiased into ratchet tooth engagement for restraining said wheel fromrotation in one direction. a load pawl carrying arm pivotally mountedaxially of said ratchet wheel and adjacent thereto to extend radiallytherefrom and oscillate thereabout within said housing, a load pawlpivotally mounted on said arm normally biased into ratchet toothengagement, a reversing ring mounted for concentric movement about theaxis of said sheave having opposed cam lobes, a spring for biasing saidring under tension in a direction for camming engagement with said pawlsto alternately move them out of ratchet tooth engagement, a manuallyoperated control member for locking said ring in inoperative positionagainst spring tension. a

kickback spring element operably associated with said reversing ring foradditionally urging it in the direction of its spring bias upon releasethereof by said manually operated control, a handle operated lever armpivotally mounted within said housing closely adjacent said ratchetWheel and pawl carrying arm, and s. link mounted within said housingconnecting the free end of said lever arm with the free end of said loadpawl carrying arm, whereby oscillation of said lever arm Within lo saidhousing will effect oscillation of said pawl carrying arm and load pawlabout the axis of said sheave.

FREDRICK W. COFFING.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 552,044 Crocker Dec. 24, 1895 1,862,331 Cofiing June 7, 19322,480,303 Pennell Aug. 30, 1949

